There's lack of payment options with "essential goods & services", like groceries, but what's your point? Any new currency, especially digital, doesn't start with supermarkets, because supermarkets tend to be owned by large corporations that are not first adopters.

If bitcoin will become a major currency, it will have to have a phase where it cannot be used in general and only with a small number of companies. That's not evidence that bitcoin will not become a major currency, it's evidence that it hasn't yet, and nobody claims it has.

What you say is true, but I don't see mass adoption anytime soon because it seems there are no essential goods and services(and perhaps more importantly complex B2B services) being bought and sold with bitcoins alone. I think it's safe to say that the majority of these vendors accepting bitcoins are turning around and converting them to USD to pay for operational costs and only a small(if any) portion of their bitcoin revenue is traded as bitcoins. It will always be that way until the large corporations that we are all beholden to, especially as businesses, accept bitcoins.

So at this point it's really an investment vehicle and a convenient method of exchange, not a replacement for fiat currencies.